There isn't really anything special with the Time Lord's mind. He's just, basically, a genius. Rigorous and passionate studies will put you on the path to having a greater intellectual capacity.

As for the "Supergirl" spell...like above, that's fantasy, that's not real magic, HOWEVER, there is an alternative. One can learn how to manipulate and live out their dreams in a more direct manner. Being able to impress your desires for reality in your dream world, can let you access those desires and live them out there...

But then werewolves and vampires were also originally beings of fiction, so how could we summon them? I've already summoned a vampire AND a werewolf to do my bidding and they were real so how could you not summon the doctor/tardis/his companions
P.S I would also like a spell to take the role of the doctor's companions. I think that will be cool, going around in a box thats bigger on the inside, fighting daleks and cybermen, or maybe have a spell that gives you parts of one of the bad guys (like the eye or gun (what ever its called)of a dalek or the gun or a cyberman (once again, I DONT KNOW ALL THE NAMES!)) instead, for the dr who fans that like the bad side more.

Anyone in a coven council position can post spells even if they know nothing about real magick.
These spells are not removed from the site because they bring a lot off footfall to the site, some people then stick around to learn reality.